Paper opacifying composition

ABSTRACT

A composition for use in the papermaking process to produce a paper having enhanced opaqueness is provided. The process using the composition to make the paper and the paper made therefrom are also provided by the present invention. The composition employs a reaction product of dimerized acid and alkanol amine, wherein the composition further includes a surfactant. To speed the production of the composition, a viscosity controlling agent, such as sodium chloride or sodium acetate, may be added thereto. The composition is added to pulp slurry during the papermaking process, and a paper made therefrom exhibits excellent qualities of opaqueness.

FIELD OF THE INVENTION

This invention relates to compositions for use in the papermakingprocess, a papermaking process employing the compositions to addopaqueness to the paper, and a paper produced using the compositions.

BACKGROUND OF THE INVENTION

The quality of paper produced from cellulose fibers (i.e. wood pulp orthe paper produced by the recycling of paper made from wood pulp) isoften judged by its opacity. Paper producers have long sought to improvethese vital characteristics so that an enhanced paper may be obtained.

This and other desired characteristics have been obtained in the past bysupplying the pulp slurry of cellulose fibers or furnish with additivesprior to the slurry entering the papermaking machine. Various additivesare well known in the art. For example, titanium dioxide powder is knownto be an excellent whitener. Titanium dioxide, however, is among themost expensive materials that may be added to the slurry. Thus, despitethe effectiveness of such material as a brightener, its use is limitedand satisfactory replacements have been needed.

Kaolin clay has also been used as a filler in paper to improvebrightness in the ultimate product. Generally, the kaolin clay iscalcined and then suspended in an aqueous solution prior to being addedto the furnish. The clay must be continuously agitated prior to enteringthe slurry or the solid particles begin to form sediment at the bottomsof the clay holding tanks. Although kaolin clay provides brightness, aswell as opacity to the finished paper product, the relative difficultyof adding it to the slurry results in a less than excellent additive.

When clay is added to the pulp slurry, the slurry needs additionalchemicals. A retention aid is necessary to retain the clay in the sheet,which will add extra cost to the sheet. Adding clay to the slurry willalso have an adverse effect on drying the sheet of paper. The papermaker will slow the paper machine down to maximize the drying to makesure the sheet is dried, which will increase the cost of the sheet. Theclay also increases wear on the paper machine. This wear shows up inshorter life for some of the pans of the paper machine. The wire, felt,doctor blade and refiners especially, show wear when clay is used. Withthe increased abrasiveness of the clay down time is longer and morefrequent.

Hydrated aluminum silicate has also been employed as a clay substitutein the papermaking process. It has properties similar to kaolin clayand, thus, results in the same disadvantages when used to make paper.

Many compositions have been added to the slurry in an attempt to sizethe paper, i.e. render the paper water repellent. Most known sizes, suchas those disclosed in U.S. Pat. No. 2,142,986 to Arnold, Jr. and U.S.Pat. No. 3,096,232 to Chapman, employ a type of wax. For example,Arnold, Jr. discloses that an emulsion of wax in a solution ofdeacetylated chitin, paraffin waxes, Japan wax, carnauba wax, higheraliphatic alcohols, or synthetic waxes may be employed as thewaterproofing agent in a sizing composition. A softening agent such asaliphatic alcohols containing 12 to 20 carbons is also present in thecomposition of Arnold, Jr. Chapman discloses the use of paraffin waxesor water-insoluble derivatives of resins for producing aqueous waxemulsions with cationic modified starches.

In U.S. Pat. Nos. 5,296,024 and 5,292,363 a papermaking composition isdisclosed for enhancing opaqueness comprising the reaction product offatty acid and diamine. This composition is effective although furtherimprovements are desired for strength of the paper, and coefficient offriction.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a composition foradding to paper during the papermaking process so that the resultingpaper has enhanced characteristics.

It is another object of the present invention to provide a compositionthat adds opacity to paper to which it is added.

Still another object of the present invention is to provide acomposition for adding to the pulp slurry of cellulose fibers to enhanceopacity without adversely affecting other paper properties.

Still another object of the present invention is to provide a processwherein a composition is added to recycled pulp of cellulose fibers toform a paper having desirable physical characteristics.

Still another object of the present invention is to provide a processfor adding a composition to pulp slurry of cellulose fibers in thepapermaking process that will result in a paper having enhanced opacity.

Yet another object of the present invention is to provide a paper havingthe desirable characteristic of enhanced opacity.

Generally speaking, the present invention is directed to a compositionused as an additive to the pulp slurry of cellulose fibers from whichpaper is formed, the process of making paper from theadditive-containing slurry, and the paper made according to thatprocess. The composition contains the reaction product of dimerized acidand alkanol amine, wherein the composition further includes asurfactant. A viscosity controlling agent may be added to thecomposition as necessary or desired; an acid may be added to adjust pH;and a defoamer may be added if needed to control foam. In a furtherembodiment the composition contains the reaction product of dimerizedacid, alkanol amine and a fatty acid.

DETAILED DESCRIPTION

The composition is added to the pulp slurry after the wood pulp has beenbleached to remove lignin and other undesirables and de-inked, ifrecycled paper pulp is being used, but before the pulp enters into theheadbox of a papermaking machine. The composition may be added alone, orin conjunction with other brighteners, opacifying agents, and sizes. Forexample, in one embodiment of the invention, the composition hereof maybe added in conjunction with papermaking clays such as kaolin, or inconjunction with a brightness and opacifying agent based on the stearicacid diamide of amino ethyl ethanolamine.

The composition may be added to any pulp slurry to obtain the desiredphysical characteristics and is especially useful for enhancing thecharacteristics of paper made from the recycled pulp of cellulosefibers. The amount of composition, as well as the amounts of eachcomponent in the composition, will vary depending on the characteristicsand types of pulp slurry to which the composition is added. As is wellknown, different sources of wood pulp have different peculiarities thatattribute to their ability to be brightened, made more opaque and morewater resistant, and easily processed. For instance, some wood pulprequires a higher concentration of brightening and opacifying agentsthan others to produce a finished paper product having identicalcharacteristics.

The composition employed in the present invention comprises the reactionproduct formed from the reaction of dimerized acid and alkanol amine andwherein the composition further includes a surfactant. This compositionprovides an increase in opacity to the paper produced and gives animproved paper strength and coefficient of friction. This composition isalso more efficient, i.e. effective at lower dosages, than an opacifyingagent based on the stearic acid diamide of amino ethyl ethanolamine.

A dimerized acid is where a molecule of an unsaturated acid is reactedwith another to form a dicarboxylic acid with a molecular weightapproximately the sum of these acids and generally is the product of amodified Diels-Alder reaction of unsaturated acids. The final productcan be a mixture of dimer, trimer, and higher compounds. Generally thedimerized acids useful herein will have from 18 to 54 carbons,preferably 21 to 40 carbons. Typically the dimer acid will have thefollowing properties: an acid value of 170-270; a color (Gardner) of6-18; a viscosity at 25° C. of 5000-10,000 cst; and a Sap value of170-202. Suitable dimer acids include dimers of poly unsaturated acidssuch as those derived from tall oil, soybean oil, palm oil, etc. or fromavailable poly unsaturated acids such as linoleic acid, linolenic acid,eleostearic acid, etc. and mixed dimers from above described polyunsaturated acid with mono-unsaturated acids such as oleic acid,propenoic acid, 2 methyl propenoic acid, butenoic acid, octadecenoicacid, etc. The preferred dimerized acids are dimerized tall oil acid,dimerized soybean oil acids and liquid mono cyclic C₂₁ dicarboxylicacid.

The alkanol amines that are useful include the monoamines, as well asthe diamines and triamines. Suitable alkanol amines include: monoethanolamine, diethanol amine, amino ethyl ethanol amine, dimethyl amino propylamine, and dimethyl amino ethyl amine and mixtures of these amines. Thepreferred amine is amino ethyl ethanol amine as it gives improvedopacity to the treated paper. Diamines, including ethylene diamine,diethylene triamine, and higher analogues can also be used with thealkanol amine to make a higher molecular weight reaction products whichhave the advantage of providing improved brightness, and strength to thetreated paper.

In a further embodiment of this invention the composition will comprisethe reaction product of the dimerized acid, alkanol amine and a fattyacid. This is generally carried out by either reacting the dimerizedacid with the alkanol amine then the fatty acid or by reacting the fattyacid with the alkanol amine and then the dimerized acid. The fatty acidpreferably is a long chain fatty acid having between 12 and 18 carbons.Suitable fatty acids include lauric acid, myristic acid, iso-stearic andpalmitic acid with the preferred acid being stearic acid. The fattyacids can also include the hydroxy substituted and/or the unsaturatedfatty acids including ricinoleic acid, oleic acid, linoleic acid andeleostearic acid.

The reaction product will generally comprise of from 60 to 85% byweight, preferably 66-84%, of dimerized acid and 15 to 40% by weight,preferably 16-34% of alkanol amine. In the further embodiment thereaction product will generally comprise from 50 to 30% by weight,preferably 55 to 35% of dimerized acid, 30 to 10% by weight, preferably20 to 15% of alkanol amine and 20 to 50%, preferably 25 to 45 of fattyacid. This reaction product base is then emulsified with a surfactant.Generally the composition comprises the following, by weight: 2-35%,preferably 7-30%, of the reaction product base; optionally 1 to 15%,preferably 2-10%, of an inorganic or organic acid; optionally 0.1 to 2%,preferably 0.2-1%, of a salt; 0.1-5 %, preferably 0.2-1%, of asurfactant; and 45-97%, preferably 70-90%, of water.

The reaction product can be prepared as follows. The dimer acid ischarged to a rosin flask equipped with an electric stirrer, condenser,and a nitrogen sparge tube. The dimer acid is heated to 70° C. to 130°C., preferably above 100° C. The amine is added slowly using an additionfunnel. The exotherm can be controlled by the addition ram. When theamine charge is complete, the batch is heated up. At 150° C. to 180° C.,water of reaction starts to distill out. Distillation will be completeat 220° C. A small amount of defoamer maybe added to help control thefoaming, if needed. When the theoretical amount of water is collected, asample is taken for an acid value. If the acid value is less than 5, thebatch is cooled. If acid value is greater than 5 cooking is continueduntil the acid value is less than 5. The reaction product can then beemulsified by heating water in a reaction vessel to 75° C. to 98° C. andcharging surfactant, acid and salt. The molten reaction product base isthen poured in at rate to keep the temperature below the boiling point.After the base is charged, the emulsion is left to stir at 90° C. for 30minutes, then cooled.

This emulsion is added to paper pulp in the wet end of a paper machinegenerally at a rate of 40 to 200 pounds per ton of paper. The finishedpaper will show an increase in opacity, while not having an adverseeffect on other paper properties including brightness, strength, andcoefficient of friction (CoF). The interest in paper opacity is toreduce the amount of inorganic filler added. This is increasinglyimportant with the increased use of recycled paper. The inorganicfillers reduce the speed of the paper machine and they also areabrasive, which adds wear and tear on the machine.

The type of pulp slurry to which the composition may be added isunimportant. In fact, the make-up of the composition may be varieddepending on the type of cellulose fibers from which the pulp slurry ismade. To increase opaqueness, additional amounts of the composition maybe employed. In addition, the use of pulp which has been recycled frompapers may require other adjustments to the composition, particularlywhen the recycled pulp is dark or otherwise discolored. All suchadjustments to the composition may be easily made by one of ordinaryskill in the art according to the invention disclosed herein.

The pulp to which the composition is added is made into a slurry usingconventional techniques. After formation, the slurry is stored inholding tanks or fed to a papermaking machine, such as a Fourdriniermachine, in a conventional manner. The pulp may be bleached to removeunwanted pollutants such as lignins and de-inked if pulp made fromrecycled paper is used. The papermaking composition disclosed herein maybe added either to the slurry when it is in the holding tank or may beadded to the slurry as it moves along to the headbox of the papermakingmachine. Preferably, the composition is applied to the pulp in theholding tank before it travels to the headbox.

When the slurry containing the composition reaches the headbox of thepapermaking machine, paper is formed therefrom using conventionalpapermaking techniques and materials. The paper produced according tothe present invention exhibits excellent characteristics of opaqueness.

In a further embodiment of the, present invention, other materials maybe added in conjunction with the composition. For instance, kaolin claymay be added in addition to the inventive composition so that the papermade therefrom exhibits increased opaqueness. Other additives which arewell known in the art may also be added in conjunction with thecomposition disclosed herein.

In addition, it is preferred that the particle size of the compositionbe as small as possible. It is highly desirable that the papers producedaccording to the present invention have substantially uniform opaquenessover its entire surface. Smaller particle sizes aid in thedispersibility of the particles within the slurry so that the desiredcharacteristics are uniform throughout the paper. These smaller particlesizes may be obtained by either homogenizing the product in a high speedmixer or by rapidly cooling the composition from the high temperature atwhich the reaction product base is formed as described herein.

Ethoxylated surfactant can be used to emulsify the base. Suitablesurfactants or combinations of surfactants including the following maybe used: stearyl amine with from 2 to 20 moles of ethylene oxide;coconut amine with from 2 to 20 moles of ethylene oxide; tallow aminewith from 2 to 20 moles of ethylene oxide; or any other ethylene oxideadduct of a fatty amine. The surfactant further contributes to thedesired dispersability of the reaction product in the water emulsion. Ifthe amount of surfactant added is excessive, the sizing capability ofthe composition will be adversely affected. In the absence of asurfactant, the paper may be of a poor quality due to the decreaseddispersibility of the composition, which results in spots or specks onthe paper indicating a lack of dispersibility.

A weak acid is preferred to disperse the reaction product. The acidmaintains an acidic pH preferably within the range of from about 4 toabout 5 during the making of the composition. The acid acts as acatalyst by creating an acidic environment wherein the cationic softenerbase exhibits increased reactivity. Inorganic acids and/or organic acidsof the following type maybe used to prepare the salt of the product tohelp stabilize the emulsion: hydrochloric acid, sulfuric acid,phosphoric acid, acetic acid, propanoic acid, etc. Weak organic acidssuch as acetic acid or formic acid are especially preferred in thecomposition. Strong acids, of course, may be used to control the pH, butcost and safety considerations may restrict their use.

Preferably, a viscosity controlling agent such as a salt is added duringproduction of the papermaking composition. Generally, the sodium saltsand potassium salts are known viscosity controlling agents includingsodium propionate, sodium acetate, potassium propionate, potassiumacetate, sodium chloride, potassium chloride. Preferred salts includesodium acetate and sodium chloride. This component may be deleted, butthe processing time for creating the composition may be substantiallyincreased.

The present invention may be better understood by reference to thefollowing examples.

Example I

368 grams of a tall oil dimerized acid (83% dimer acid, 15.5% trimeracid, 1.5% monomer acid) was charged to a liter resin flask. Thenitrogen sparge was set on low. The dimer acid was then heated to 100°C. and 132 grams of amino ethyl ethanol amine was charged over 10minutes. The batch was slowly heated to 200° C. The batch was held at200° C. for an hour and the acid value was checked. It was less than 5.The batch was cooled to 125° C. While the batch was cooling, to a 2liter resin flask the following items were charged: 40 grams of 84%acetic acid, 12 grams of CAM 2 POE (coconut amine with 2 moles ethyleneoxide), 1 gram of potassium acetate and 1000 grams of water. The mixtureunder agitation was heated to 80° C., and the reaction product base at125° C. was slowly poured in. The solution was held at 90° C. for thirtyminutes and cooling was started. Adjustments were made, and the finalsolution was a 30% non-volatile solids and clear amber.

Example II

419 grams of a tall oil dimerized acid (83% dimerized acid, 1.5%monomer, 15.5% trimer) was charged following the same procedure as inExample I. Then 37 grams of diethylene triamine and 44 grams ofmonoethanol amine were charged. The final product was cooled to roomtemperature. It was an amber viscous liquid with an acid number of 2.7and an amine number of 41. To 265 grams of water was charged 0.8 gramsof TAM 15 POE (tallow amine, 15 moles ethylene oxide), 2.2 grams of 84%acetic acid, 0.5 grams of 25% sodium hydroxide and 33 grams of thereaction product base. The solution was heated to 90° C. and held for 30minutes. The while milky emulsion was cooled down and the solids wereadjusted to 11%.

Example III

737 grams of a tall oil 95% dimer acid (95% dimer acid, 4% trimer acidand 1% monomer acid) and 264 grams of amino ethyl ethanol amine werecharged and the same procedure was followed as Example I. The emulsionwas prepared same as the emulsion in Example II. It was adjusted to 10%non-volatile solids with a milky white emulsion.

Example IV

375 grams of a tall oil dimerized acid (60% trimer acid and 40% dimeracid) was charged to a 2 liter round bottom flask. The contents of theflask were heated to 90° C. and 125 grams of amino ethyl ethanol aminewas charged. The temperature was allowed to exotherm to 130° C. duringthe amine charge. The batch was heated to 180° C. and the distillatecollected. When the acid value was less than 5, then batch was cooleddown and put in a can. 15 grams of base, 265 grams of water, 5 grams of84% acetic acid, 0.7 grams of SAM 5 POE (stearyl amine with 5 molesethylene oxide) and 0.25 grams of potassium hydroxide were heated to 90°C. and held for 30 minutes. The milky white emulsion was adjusted to 5%non-volatile solids.

Example V

369 grams of a tall oil dimerized acid (83% dimer acid, 1.5% monomeracid and 15.5% trimer acid) was charged with 98 grams of amino ethylethanol amino and 33 gins of dimethyl amino propylamine. The sameprocedure was used as Example I. The emulsion was prepared as in ExampleII.

Example VI

To 396 grams of a tall oil dimerized acid (83% dimer acid, 1.5% monomeracid, 15.5% trimer acid) was added 36 grams diethylene diamine and 68grams of amino ethyl ethanol amine. The same procedure was followed asdescribed in Example I. 33 grams of base was charged to 260 grams ofwater, 1 gram of TAM 15 POE (tallow amine with 15 moles ethylene oxide)and 10 grams of 84% acetic acid. The emulsion prepared as in Example IImade a milky white emulsion.

Example VII

331 grams of dimer acid (reaction product of linoleic acid and acrylicacid) was reacted with 169 grams of amino ethyl ethanol amine. The sameprocedure as described in Example I was used to emulsify the viscousproduct.

Example VIII

The emulsions of the reaction product prepared in Examples I, II and IVwere tested by preparing hand sheets 8×8 inches by adding the followingamounts of the Example I, II and IV samples to a furnish containing thewood pulp. These samples were compared against a blank and against aComparative sample containing the stearic acid diamide of amino ethylethanolamine (see U.S. Pat. No. 5,296,024). The sheets after pressing at40 psig to squeeze out water are dried at 240° F., then conditioned(TAPPI standard T402 OM-88), then calendared at 150° F. and 600 psi.

The hand sheets were tested as follows: brightness and opacity weremeasured on a Technobrite instrument with an average of five readingsbeing taken; the Mullen-Burst test measuring strength were run accordingto TAPPI standard T403 OM-85; the Scott Bond internal bond strength wasmeasured on a Scott Bond tester; the tear resistance was measured on anElmendorf tester according to TAPPI procedure T414/OM-88; and the CoF(coefficient of friction) was measured by a slide angle tester Model TMI3225. The hand sheets were tested with the following results.

    __________________________________________________________________________    Recycled Pulp (gms)                                                                      60 60 60 60 60 60 60 60 60                                         Comparative (gms)                                                                           4  8                                                            Example I (gms)     4  8                                                      Example II (gms)          4  8                                                Example IV (gms)                4  8                                          Test Results                                                                  Brightness 57.0                                                                             57.7                                                                             57.0                                                                             53.5                                                                             52.1                                                                             55.0                                                                             53.8                                                                             54.3                                                                             53.7                                       Opacity (TAPPI)                                                                          95.5                                                                             94.5                                                                             96.6                                                                             97.7                                                                             97.8                                                                             95.9                                                                             97.1                                                                             96.6                                                                             97.1                                       Mullen Burst                                                                             7.8                                                                              5.1                                                                              3.3                                                                              4.0                                                                              4.0                                                                              5.0                                                                              5.0                                                                              7.0                                                                              6.3                                        CoF        21.5                                                                             19.0                                                                             19.0                                                                             20.5                                                                             23.5                                                                             22.0                                                                             22.5                                                                             21.5                                                                             22.5                                       Scott bond 45.0                                                                             32.4                                                                             28.8                                                                             33.5                                                                             37.5                                                                             33.0                                                                             38.5                                                                             38.7                                                                             37.8                                       __________________________________________________________________________

All of the sheets of paper made from the Example I, II and IV sampleshave higher opacity than the pulp. The sheets prepared from the Examplessamples all had higher CoF than the Comparative sample. In addition, thesheets produced with the Examples samples had strength properties whichwere not diminished as in the Comparative sample.

Example IX

All of the reaction product bases prepared in Example I thru VII wereviscous liquids with the following properties:

    ______________________________________                                               Acid Number                                                                             Amine Number                                                                              Color Gardner                                    ______________________________________                                        Example I                                                                              2.0         141.0       10                                           Example II                                                                             2.7         41.0        11                                           Example III                                                                            1.2         149.0        6                                           Example IV                                                                             1.0         123.0       13                                           Example V                                                                              3.8         112.6       10                                           Example VI                                                                             1.3         101.0       13                                           Example VII                                                                            3.7         174.3       14                                           ______________________________________                                    

The emulsions of the reaction products of Examples I thru VII weretested as described in Example VIII at a level of 13.2 dry pounds ofsample per ton of paper product with the following test results.

    __________________________________________________________________________              Blank                                                                              #1 #2 #3 #4 #5  #6 #7                                          __________________________________________________________________________    Pulp (gms)                                                                              60   60 60 60 60 60  60 60                                          Example I (gms)                                                                              4                                                              Example II (gms)  4                                                           Example III (gms)    4                                                        Example IV (gms)        4                                                     Example V (gms)            4                                                  Example VI (gms)               4                                              Example VII (gms)                 4                                           Test Results                                                                  Brightness                                                                              57.0 53.5                                                                             55.0                                                                             54.2                                                                             54.3                                                                             54.1                                                                              53.0                                                                             54.8                                        Opacity (TAPPI)                                                                         95.5 97.7                                                                             95.9                                                                             97.0                                                                             96.6                                                                             97.0                                                                              96.4                                                                             95.5                                        Opacity (ISO)                                                                           91.9 95.5                                                                             92.2                                                                             94.3                                                                             93.5                                                                             94.3                                                                              92.9                                                                             92.3                                        Mullen    7.8  4.0                                                                              5.0                                                                              6.2                                                                              7.0                                                                              6.4 6.0                                                                              4.5                                         Scott Bond                                                                              45.0 33.5                                                                             33.0                                                                             37.0                                                                             38.7                                                                             37.3                                                                              38.4                                                                             31.0                                        Tear      50.4 45.6                                                                             43.2                                                                             52.8                                                                             40.8                                                                             40.8                                                                              36.8                                                                             39.9                                        CoF       21.5 20.5                                                                             22.0                                                                             22.0                                                                             21.5                                                                             21.5                                                                              21.5                                                                             21.0                                        __________________________________________________________________________

The emulsions of the reaction product were then tested at level of 26.4dry pounds of sample per ton of paper product with the following testresults.

    __________________________________________________________________________              Blank                                                                              #1 #2 #3 #4 #5  #6 #8                                          __________________________________________________________________________    Pulp (gms)                                                                              60   60 60 60 60 60  60 60                                          Example I (gms)                                                                              8                                                              Example II (gms)  8                                                           Example III (gms)    8                                                        Example IV (gms)        8                                                     Example V (gms)            8                                                  Example VI (gms)               8                                              Example VII (gms)                 8                                           __________________________________________________________________________              Blank                                                                              #1 #2 #3 #4 #5  #6 #7                                          __________________________________________________________________________    Brightness                                                                              57.0 52.1                                                                             53.8                                                                             52.9                                                                             53.7                                                                             53.1                                                                              52.1                                                                             53.1                                        Opacity (TAPPI)                                                                         95.5 97.8                                                                             97.1                                                                             97.2                                                                             97.1                                                                             96.8                                                                              97.1                                                                             96.8                                        Opacity (ISO)                                                                           91.9 95.6                                                                             94.2                                                                             94.6                                                                             94.4                                                                             93.8                                                                              94.3                                                                             92.5                                        Mullen    7.8  4.0                                                                              5.0                                                                              5.0                                                                              6.3                                                                              5.2 6.3                                                                              5.9                                         Scott Bond                                                                              45.0 37.5                                                                             38.3                                                                             37.0                                                                             37.8                                                                             35.9                                                                              37.7                                                                             38.0                                        Tear      50.4 41.6                                                                             52.0                                                                             48.8                                                                             43.2                                                                             44.8                                                                              27.6                                                                             39.8                                        CoF       21.5 23.5                                                                             22.5                                                                             22.0                                                                             22.5                                                                             22.0                                                                              22.5                                                                             21.5                                        __________________________________________________________________________

The above results show the opacity of the paper is greatly increasedwith the addition of the organic opacity agent.

Example X

To a reaction vessel equipped with a heating source and an agitator 273grams of dimer acid (83% dimer, 15.5% trimer acid and 0.5% monomer acid)was charged. The acid was heated to 100° C. under an inert atmosphereand 97 grams of amino ethyl aminoethanol was slowly charged. Thetemperature was maintained at less than 110° C. during the charge. Thebatch was slowly heated to 200° C. The temperature was held at 200° C.for an hour and the acid value 2.8 mg of KOH per gram sample wasmeasured. At that point 130 grams of 70% stearic acid and 30% palmiticacid was charged. The temperature was maintained at 200° C. for one andhalf hours. A sample was drawn, the acid value was checked on the sampleand it was less than 5.0 mg of KOH per gram of sample. The heatingsource was removed from the reaction vessel, and the batch was allowedto cool to 90° C. The tan solid melted at 40° C., had an acid value of4.4 mg of KOH per gram of sample, and an amine value of 59 mg of KOH pergram of sample.

The product prepared a white emulsion using the procedure as describedin Example I.

Example XI

To a suitable reaction vessel was charged 237 grams of 70% stearic acidand 30% palmitic acid. The acid was heated to 100° C. with, a nitrogenblanket during the heat up cycle. To the acid, 89 grams of amino ethylamino ethanol was charged. The temperature was maintained below 110° C.during the charge. The batch was heated to 200° C. At 200° C., the acidvalue was checked and is 3.0 mg of KOH per gram of sample. 175 grams ofdimer acid (83% dimer acid, 15.5% trimer acid, and 1.5% monomer acid)was charged. The temperature was maintained at 200° C. for four hoursuntil the acid value was less than 5.0. The batch was allowed to cool to90° C. The light tan solid melted at 55° C. It had an acid value of 2.8mg of KOH per gram of sample and an amine number of 31.6 mg of KOH pergram of sample.

The tan solid was emulsified using the procedure described in Example Iand was tested as described in Example VIII versus the blank and thesame Comparative Sample.

    ______________________________________                                                   1    2          3      4                                           ______________________________________                                        Virgin Pulp  60     60         60   60                                        Retention aid                                                                              0.5    0.5        0.5  0.5                                       Comparative  --     8.0        --   --                                        Example XI   --     --         4.0  8.0                                       Test Results                                                                  Brightness   53.0   54.3       53.8 55.1                                      Opacity      96.3   97.0       96.8 96.7                                      Mullen Burst 6.4    4.3        6.0  6.2                                       Tensile      3.0    2.8        3.8  3.5                                       ______________________________________                                    

These Example XI samples show an increase in opacity and brightnessmaking a stronger sheet with Mullen Burst and tensile equivalent to theuntreated paper. The Comparative sheet is weaker than the Example XIsheets.

What is claimed is:
 1. A composition for adding to a pulp slurry ofcellulose fibers during a papermaking process for enhancing opaquenessin the paper produced therefrom comprising the reaction products formedfrom the reaction of a dimerized acid and an alkanol amine and whereinsaid composition further includes a surfactant wherein the dimerizedacid is a dimer of a poly unsaturated acid selected from the groupconsisting of tall oil acid, soybean oil acid, palm oil acid, linolenicacid, eleostearic acid and mixtures thereof.
 2. The composition asdefined in claim 1 wherein the reaction product is formed from thereaction of 60 to 85% by weight of a dimerized acid and 15-40% by weightof alkanol amine.
 3. The composition as defined in claim 1 wherein saiddimerized acid has a carbon chain length of 18 to 54 carbons.
 4. Thecomposition as defined in claim 1 wherein the dimerized acid is selectedfrom the group consisting of dimerized tall oil acid, dimerized soybeanoil acid, monocyclic C₂₁ dicarboxylic acid and mixtures thereof.
 5. Thecomposition as defined in claim 2 wherein the dimerized acid has acarbon chain length of 21 to 40 carbons.
 6. The composition as definedin claim 1 wherein the alkanol amine is selected from the groupconsisting of monoethanol amine, diethanol amine, amino ethyl ethanolamine, dimethyl amino propyl amine, dimethyl amino ethyl amine andmixtures thereof.
 7. The composition as defined in claim 1 wherein saidalkanol amine is mixed with a diamine.
 8. A composition for adding to apulp slurry of cellulose fibers during a papermaking process forenhancing opaqueness in the paper produced therefrom comprising thereaction products formed from the reaction of a dimerized acid and anamino ethyl ethanol amine and wherein said composition further includesa surfactant.
 9. The composition as defined in claim 1 further includingan acid.
 10. The composition as defined in claim 1 further including aviscosity control agent.
 11. The composition as defined in claim 1wherein said surfactant is present in an amount of at least about 0.2%by weight.
 12. A composition for adding to a pulp slurry of cellulosefibers during a papermaking process for enhancing opaqueness in thepaper produced therefrom comprising the reaction products formed fromthe reaction of a dimerized acid, an alkanol amine and a fatty acid andwherein said composition further includes a surfactant wherein thedimerized acid is a dimer of a poly unsaturated acid selected from thegroup consisting of tall oil acid, soybean oil acid, palm oil acid,linolenic acid, eleostearic acid and mixtures thereof.
 13. Thecomposition as defined in claim 12 wherein the dimerized acid andalkanol amine are first reacted then the fatty acid is reactedtherewith.
 14. The composition as defined in claim 12 wherein the fattyacid and alkanol amine are first reacted then the dimerized acid isreacted therewith.
 15. The composition as defined in claim 12 whereinthe reaction product is formed from the reaction of 50 to 30% by weightof a dimerized acid, 30 to 10% by weight of alkanol amine and 20 to 50%by weight of fatty acid.
 16. The composition as defined in claim 12wherein said dimerized acid has a carbon chain length of 18 to 54carbons.
 17. The composition as defined in claim 12 wherein thedimerized acid is selected from the group consisting of dimerized talloil acid, dimerized soybean oil acid, mono cyclic C₂₁ dicarboxylic acidand mixtures thereof.
 18. The composition as defined in claim 16 whereinthe dimerized acid has a carbon chain length of 21 to 40 carbons. 19.The composition as defined in claim 12 wherein said alkanol amine ismixed with a diamine.
 20. The composition as defined in claim 12 whereinthe alkanol amine is selected from the group consisting of monoethanolamine, diethanol amine, amino ethyl ethanol amine, dimethyl amino propylamine, dimethyl amino ethyl amine and mixtures thereof.
 21. Acomposition for adding to a pulp slurry of cellulose fibers during apapermaking process for enhancing opaqueness in the paper producedtherefrom comprising the reaction products formed from the reaction of adimerized acid, an amino ethyl ethanol amine and a fatty acid andwherein said composition further includes a surfactant.
 22. Thecomposition as defined in claim 12 wherein the fatty acid has a carbonchain length between 12 and 18 carbons.
 23. The composition as definedin claim 22 wherein the fatty acid is selected from the group consistingof lauric acid, myristic acid, iso-stearic acid, palmitic acid, stearicacid, ricinoleic acid, oleic acid, linoleic acid, eleostearic acid andmixtures thereof.
 24. The composition as defined in claim 12 wherein thefatty acid is stearic acid.
 25. The composition as defined in claim 12further including a viscosity control agent.
 26. The composition asdefined in claim 12 further including an acid.